Radiolysis and Photolysis of Icy Satellite Surfaces: Experiments and Theory

The transport and exchange of material between bodies in the outer solar system is often facilitated by their exposure to ionizing radiation. With this in mind we review the effects of energetic ions, electrons and UV photons on materials present in the outer solar system. We consider radiolysis, photolysis, and sputtering of low temperature solids. Radiolysis and photolysis are the chemistry that follows the bond breaking and ionization produced by incident radiation, producing, e.g., O2 and H2 from irradiated H2O ice. Sputtering is the ejection of molecules by incident radiation. Both processes are particularly effective on ices in the outer solar system. Materials reviewed include H2O ice, sulfur-containing compounds T. Cassidy ( ) · R.E. Johnson Engineering Physics Program, University of Virginia, Charlottesville, VA 22904, USA e-mail: [email protected] Present address: T. Cassidy Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA P. Coll Laboratoire Interuniversitaire des Systèmes Atmosphériques, Université Paris 7 Denis Diderot, Créteil, France F. Raulin Laboratoire Interuniversitaire des Systèmes Atmosphériques, UMR 7583, Université Paris 7 et Paris 12, CNRS, Créteil, France R.W. Carlson · K.P. Hand Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA R.E. Johnson Physics Dept., New York University, New York, NY 10003, USA M.J. Loeffler Astrochemistry Laboratory, NASA Goddard Spaceflight Center, Greenbelt, MD, USA R.A. Baragiola Laboratory for Atomic and Surface Physics, University of Virginia, Charlottesville, VA 22904, USA